1. Field of the Invention
The present invention relates to the removal of cholesterol from foods using β-cyclodextrin (hereinafter referred to as “β-CD”) as a trap. More particularly, the present invention relates to a method for trapping cholesterol from foods in crosslinked β-CD and recycling the cholesterol-trapped β-CD with an organic solvent.
2. Description of the Related Art
A strong positive correlation is reported to exist between blood cholesterol level and the risk of adult diseases in the circulatory system. For this reason, western foods, including milk, dairy products, other animal resourced foods, etc., that are rich in cholesterol have recently been the object of concern among people.
Most animal resourced foods have cholesterol. Its content is measured to be 219 mg/100 g of butter, 137 mg/100 g of 36% fat cream, 105 mg/100 g of cheddar cheese, 95 mg/100 g of cream cheese, 87.5 mg/100 g of blue cheese, 122.9 mg/100 g of fetta cheese, 112 mg/100 g of lard, and 1,050 mg/100 g of egg yolk.
The only way to prevent diseases resulting from the excessive intake of cholesterol is to consume low or zero-cholesterol foods. Active research into the physical, chemical and/or biological reduction of cholesterol in foods including dairy products has been conducted.
One of the most effective methods for the reduction of cholesterol content in dairy products is to use β-CD as an absorbent. This absorbent binds cholesterol to form a water-insoluble β-CD-cholesterol complex which can be readily centrifuged out.
β-CD is one of the circular α-(1,4)-linked oligosaccharides produced by the catalytic reaction of cyclodextrin-glycosyltransferase, an enzyme found in microorganisms, with starch, and is nontoxic to the body (see FIG. 1). β-CD has a cavity at the center of its molecular arrangement, which forms an inclusion complex with various compounds including cholesterol. Also, beta-CD is nontoxic, edible, nonhygroscopic, chemically stable, and easy to separate from the complex. Therefore, β-CD is a suitable material for removing cholesterol from foods.
Beta-CD, although having the advantage of removing cholesterol from various foods at an efficiency of about 90% or higher, suffers from the disadvantages of being economically unfavorable and causing environmental pollution because of the consumption of lots of β-CD due to its ineffective recovery. To overcome these problems, the recovery and recycling of β-CD has been studied. Suggested was the use of organic solvents in recovering and recycling β-CD (see FIG. 2). However, β-CD can be recovered to some extent when applied to milk, but is difficult to separate from some foods, such as creams.
The use of β-CD in removing cholesterol is disclosed in many patents, for example, Korean Pat. Laid-Open Publication No. 1999-0015191, entitled “method for removing cholesterol from cream”, No. 1999-0015192, entitled “method for cholesterol removal using immobilized cyclodextrin derivatives”, No. 2004-0054319, entitled “method for preparing cholesterol-removed whipping cream”, No. 2003-0078532, entitled “method for removing cholesterol from cheese”, and No. 2003-0035341, entitled “cyclodextrin derivative immobilized on solid and preparation thereof”. These techniques, however, have a poor removal rate and are not suitable for industrial application.
Therefore, there is a need for a method for removing cholesterol from foods with a great economical profit.